The story
Referring to the tufts of stereocilia that protrude from the apical surface of the cell, a structure known as the hair bundle, into the scala media, a fluid-filled tube within the cochlea.
Etymology from Wiktionary, CC BY-SA 4.0.
hair cell
Today it means: Any of the sensory receptors of both the auditory system and the vestibular system in all vertebrates. Full definition →